Modular heat exchanger

ABSTRACT

A modular heat exchanger having a core of a plurality of individual core elements supported within a separate, removable heat exchanger case.

Jan. 18, 1972 References Cited [54] MODULAR HEAT EXCHANGER UNITED STATESPATENTS inventor: David L. Satchwell, Rolling Hills Estates,

Calif.

2,360,123 Gerstung et al.... 2,778,606 Lloyd et al..... 3,461,956

[73] Assignee: The Garrett Corporation, Los Angeles,

Calif.

Filed: I969 Primary Examiner-Charles Sukalo l I L 79 933 Attorney-AlbertJ. Miller and John N. Hazelwood [57] ABSTRACT A modular heat exchangerhaving a core of a plurality of in- [52]U.S.Cl......................i.,...........165/37,165/76, l65/i52dividual core elements supported within a separate, removable heatexchanger case.

mm B8. 2 m w [5!] int. [58] Field ofSearch 12 Claims, 5 Drawing Figures3 3? f I f I 2. i wwwww w .355

PATENTED JAN 1 8 I972 SHEET 1 [IF 3 INVENTOR. DAVID L. SATCHWELL- 1;! gW LJC/QLK ATT NEY (ilk,

Pimmm .mu 8 m2 SHEET 3 BF 3 INVENTOR DAVID L. SATCHWELL FIG?) W/J LLULATTOR EY 1 MODULAR IIEAT EXCI-IANGER BACKGROUND OF THE INVENTION Thisinvention relates generally to heat exchangers and more particularly toa modular heat exchanger made up of individual core elements supportedby a removable case having two sections removably jointed together.

In prior heat exchangers, particularly those adapted for the cooling ofcongealable fluids such as lubricating oils, the development of a leakor other defect in the heat exchanger core required disposal of theentire heat exchanger including the case. The integral case and corealso imposed severe vibration problems in many instances and did notpermit flexibility with respect to the size of the core to meet varyingheat transfer requirements. Also, location of the integral case and corerelative to the source of fluid to be cooled could not be optimized. Inaddition, despite many exotic solutions, start up of the heat exchangerat low temperatures still presented problems.

BRIEF SUMMARY OF THE INVENTION This invention provides a modular heatexchanger core element which can be stacked with like elements to form amodular heat exchanger core. The individual core elements each includean integral header to achieve parallel flow paths through core elements.

The heat exchanger core, made up of any number of stacked core elements,is supported by a two-section heat exchanger case can be removed topermit maintenance and separate replacement of individual core elementsor of the entire core. Resilient pads can be provided at the points ofsupport to isolate the core from vibration. A warm up tube in parallelwith the core elements and with its flow controlled by heat responsivevalve means can be utilized when required for start up. Further, onesection of the heat exchanger case can be integral with the sourceoffluid to be cooled.

It is, therefore, an object of this invention to provide an individualheat exchanger core element which may be stacked with like elements tofonn a modular heat exchanger core.

Another object of this invention is to provide an individual heatexchanger core element having an integral header and adapted to bestacked into a modular heat exchanger core with the individual elementshaving parallel flow paths.

Yet another object of this invention is to provide a modular heatexchanger in which the core can be removed from its case and separatelymaintained.

Still another object of this invention is to provide a modular heatexchanger in which the heat exchanger core is isolated from casevibrations.

A still further object of this invention is to provide a modular heatexchanger in which a section of the heat exchanger case is integral withthe source of fluid to be cooled.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a perspective view,partially cut away, of a modular heat exchanger core element,

FIG. 2 is a side elevation view, partially cut away, of the modular heatexchanger,

FIG. 3 is a top plan view of the modular heat exchanger of FIG. 2,

FIG. 4 is a cross-sectional view taken along line 44 of FIG. 2,

FIG. 5 is a side elevation view, partially cut away, of the modular heatexchanger where one section of the heat exchanger case is integral withan engine crankcase.

DETAILED DESCRIPTION OF INVENTION The individual heat exchanger coreelement which can be stacked to form a modular heat exchanger core isillustrated in FIG. 1. Basically this element shown in a counterflowconfiguration for purposes of illustration only, is made up of twoformed tube plates 12 and 14 which are joined at their periphery to forman enclosed structure. The enclosed structure is divided into an inletsection 18 and an outlet section 16, by either the shape of the formedtube plates 12 and 14 or by a restriction (not shown) placed between thetwo plates 12 and 14 when they are joined together. In the counterflowconfiguration shown, the inlet section 18 and outlet section 16 willcommunicate with each other at the bottom of the core element 10.

An inlet header 26 is provided at the top of the inlet section 18 andincludes an inlet 30, and outlet 23 on opposite sides thereof. An inletheader 20 also having an inlet 24 and outlet 22 is provided at the topof the outlet section 16. I

Both the inlet section 18 and outlet section 16 are provided with heattransfer surfaces such as fin sheets 34 and 32 respec tively. Thesesheets may be of the rectangular offset type as illustrated.

The individual core elements 10 can be constructed of a lightweightstructural material having good heat transfer characteristics such asaluminum and may be individually brazed, for example, in a salt bath dipto form the structure invblved;

The individual core elements 10 can be stacked together to form amodular heat exchanger core 40, as shown in FIG. 2. The number and sizeof the individual core elements 10 would be determined by the heattransfer requirements for the heat exchanger. The elements 10 would bejoined at theirrespective headers to permit flow from one inlet headerto an adjacent inlet header and likewise from one outlet header to anadjacent outlet header. Fin sheets 42 can be provided between individualcore elements 10 to increase heat dissipation from the fluid within thecore elements.

The individual core elements 10 including the tin sheets 42 may bebrazed together to form an integral unit if desired. Also, the brazingof the individual core elements can be deferred and the entire coreassembly brazed at the same time. If however, the individual coreelements are not to be brazed together, gaskets 43 can be providedbetween the outlet and inlet of adjacent headers.

As shown in FIGS. 2 and 3, the heat exchanger case 50 is made up of twoseparate sections 52 and 54 which are joined together to support themodular core 40. The first section 52 and second section 54 of the case50 may be provided with lugs 56 and 58 respectively by which bolts 59can be used to secure the attachment of the first section 52 to thesecond sec tion 54. Integral nuts 57 in the lugs 56 of the first sectionprovide for a secure attachment. Resident pads 60 of a material such asfelt can be used between the case 50 and modular core 40 at points ofsupport to provide vibration isolation for the core. The second section54 of the heat exchanger case 50can be provided in varying lengths toaccommodate different heat exchanger core sizes.

A warm up tube 62 can be provided in the modular heat exchanger core 40,particularly when the heat exchanger is to be used to cool a congealablefluid. This warm up tube 62, like the individual core elements 10, isdivided into an inlet section 64 and an outlet section 66. As shown inFIG. 4, an inlet 68 provided in the firstsection 52 of the case 50communicates with an inlet 70 in the inlet section 64 of the warm uptube 62. An outlet 72 in the inlet section 64 of the warm up tube 62communicates with the inlet 30 of the inlet header 26 of the adjacentcore element 10. 7

An outlet 74 in the outlet section 66 of the warm up tube 62communicates with a first outlet 76 in the first case section 52. Aconduit 78 through the outlet section 66 of the warm up tube 62 permitsa direct flow from the outlet 22 of the outlet header 20 of the adjacentcore element It) to the second outlet 80 of the first case section 52.Gaskets 69 and 75 may be pro vided to prevent leakage between inlets 68and 70 and between outlets 74 and 76 respectively, while an O-ring 79prevents leakage between conduit 78 and outlet 80.

The flow of fluid through the first outlet 76 is controlled by a heatresponsive valve 82, such as a Vernatherm valve, Vernathenn being atrademark of American Standard. Both the inlet and outlet sections 64and 66 of the warm up tube 62 can be provided with a plurality ofindividual fins 84 and 85, respectively to increase the heat transfersurfaces within the warm up tube 62 with a minimum resistance to fluidflow.

While the above-described heat exchanger can be used for a variety offluids, it is particularly useful for congealable fluids such aslubricating oils used to cool and lubricate an internal combustionengine and the operation of the heat exchanger will be described in thisrespect. In the start up of the heat exchanger, particularly at lowertemperatures, the core 40 will be full of congealed oil. As the flow ofoil from the crankcase of an internal combustion engine is initiated, itwill take the path of least resistance namely through the inlet 70 ofthe warm up tube 62 into the inlet section 64 of the warm up tube,through the inlet section 64 and outlet section 66 of the warm up tubeand out through the outlet 74 of the outlet section 66 of the warm uptube 62 to the first outlet 76 of the case 50. The valve 82 is designedto permit the flow of oil through the first outlet 76 at lowtemperatures and to shut off the flow at higher temperatures. Thisinitial flow path at low temperature principally results from the factthat the resistance to flow through the inlet and outlet sections 16 and18 of the individual core elements is much greater than the resistanceto flow through the warm up tube 62.

As the temperature of the flowing oil rises, the heat from the oilpassing through the warm up tube 62 will start to decongeal thecongealed oil in the core element 10 adjacent to he warm up tube 62.Also, as the oil increases in temperature, the heat responsive valve 82will start to close thereby increasing the resistance flow through thewarm up tube 62.

The interaction of the above two factors, will, as the temperature ofthe oil increases, initiate flow first through the core element adjacentto the warm up tube 62 and successively through the next adjacentindividual core elements and extending eventually the entire length ofthe modular core 40. When a sufficient temperature has been reached, thevalve 82 will completely shut off flow through the first outlet 76 ofthe case and in essence remove the warm up tube 62 from the flow throughthe core 40.

While the individual core elements have been shown as providing a seriesof parallel flows from the in-line headers, it should be recognized thatmany alternate flow and header configurations are possible. The numberof core elements making up an individual core can be varied in responseto heat transfer requirements. The separate nature of the core and casepermits the maintenance and replacement of the core with relative case.This separate arrangement also permits the first section of the case tomade integral with the source of congealable fluid to be cooled as shownin FIG. 5. The crankcase 90 of an internal combustion engine can beprovided with an upper projection 92 and a lower projection 94 whichcorresponds to the first section 52 of the heat exchanger case 50. Theseprojections 92 and 94 include lugs 56 having integral nuts 57 to enableattachment to the lugs 58 of the second case section 54 by means ofbolts 59. The second section 54 can be identical to that previouslydescribed in FIGS. 2 and 3. The inlet and outlets to the heat exchangercore 40 would be included in the crankcase 90 in a manner similar tothat described in FIG. 4. The heat responsive valve 82 is mounteddirectly in the crankcase 90, as shown.

While specific embodiments of the present invention have beenillustrated and described in considerably detail, it should berecognized that modifications can be made thereto without departing fromthe spirit and scope of the invention as defined in the appended claims.

What I claim is:

1. A modular heat exchanger comprising:

a modular heat exchanger core having a plurality of substantiallyidentical individual core elements; and

a heat exchanger core case positioned around said core and having afirst section and a second section, said second core case sectiondetachably secured to said first core case section to removably supportsaid core.

2. The modular heat exchanger of claim I wherein said individual coreelements comprise:

a first tube plate;

a second tube plate substantially identical to said first tube plate,the outer periphery of said first tube plate joined to the outerperiphery of said second tube plate to form an enclosure between saidsecond tube plates;

restricting means within said enclosure defining an inlet section and anoutlet section within said enclosure;

said inlet section of said enclosure having an inlet header at the oneend thereof, said inlet header having an inlet on one side thereof andan outlet on he opposite side thereof;

said outlet section of said enclosure having an outlet header at the oneend thereof, said outlet header having an inlet on one side thereof andan outlet on the opposite side thereof;

a first fin sheet positioned within said inlet section of saidenclosure; and

a second fin sheet 'positioned within said outlet section of saidenclosure.

3. The modular heat exchanger of claim 2 and in addition a plurality ofindividual fin sheets, an individual fin sheet positioned betweenadjacent individual core elements.

4. The modular heat exchanger of claim 1 wherein said first section andsaid second section of said heat exchanger core case are boltablysecured to each other.

5. The modular heat exchanger of claim 1 and in addition resilientmaterial pads interposed between said heat exchanger core and said heatexchanger core case at points of support.

6. The modular heat exchanger of claim 1 and in addition a fluid cooledoperably associated with said heat exchanger and wherein said firstsection of said heat exchanger core case is an integral part of saidengine.

7. A modular heat exchanger for a congealable fluid comprising:

a modular heat exchanger core having a plurality of substantiallyidentical individual core elements, and individual core elementscomprising:

a first tube plate;

a second tube plate substantially identical to said first tube plate,the outer periphery of said first tube plate joined at the outerperiphery of said second tube plate to form an enclosure between saidfirst and said second tube plate;

restricting means disposed within said enclosure defining an inletsection extending the length of one side of said enclosure and an outletsection extending the length of the opposite side of said enclosure,said inlet section communicating with said outlet section at the bottomof said enclosure;

said inlet section of said enclosure having an inlet header at the upperend thereof, said inlet header having an inlet on one side thereof andan outlet on the opposite side thereof, said inlet adapted tocommunicate with the outlet of the inlet header and an adjacent coreelement on one side of said inlet header and said outlet adapted tocommunicate with the inlet of the inlet header of an adjacent coreelement on the opposite side of said inlet header;

said outlet section of said enclosure having an outlet header at theupper end thereof, said outlet header having an inlet on one sidethereof and an outlet on the opposite side thereof, said inlet adaptedto communicate with the outlet of the outlet header of an adjacent coreelement on one side of said outlet header and said outlet adapted tocommunicate with the inlet of the outlet header of an adjacent coreelement on the opposite side of said outlet header;

a first fin sheet positioned within said inlet section of saidenclosure, and

a second fin sheet positioned within said outlet section of saidenclosure;

a plurality of individual fin sheets, an individual fin sheet positionedbetween adjacent individual core elements below said inlet and outletheaders;

a heat exchanger core case positioned around said core and having afirst section at one end of said core and a second section at the otherend of said core and boltably attached to the first case section, saidfirst case section having an inlet to provide a flow of eongealablefluid to said core and two outlets to receive a flow of congealablefluid from said core;

a warm up tube interposed between said first case section and said heatexchanger core;

restricting means disposed within said warm up tube defining an inletsection extending the length of one side of said warm up tube and anoutlet section extending the length of the other side of said tube, saidinlet section communicating with said outlet section at the bottom ofsaid tube;

said inlet section of said warm up tube having an inlet to receive aflow of congealable fluid to the inlet section of said warm up tube fromthe inlet of said first section of said case and an outlet opposite saidinlet to communicate with the inlet of the inlet header of the adjacentindividual core element;

said outlet section of said warm up tube having an outlet to permit aflow of congealable fluid from the outlet section of said warm up tubeto the first outlet of said first section of said case and conduit meansthrough said outlet section of said warm up tube to providecommunication between the outlet of the outlet header of the adjacentindividual core element and the second outlet of the first section ofsaid case;

a plurality of fins positioned within said inlet and said outletsections of said warm up tube, said fins to provide less resistance tothe flow of congealable fluid than said first and said second fin sheetsin the inlet and outlet sections of the individual core elements; and

heat responsive valve means in the first outlet of said first section ofsaid case to permit the flow of cold congealable fluid and restrict theflow of wamt congealable fluid.

8. The modular heat exchanger of claim 1 wherein said first and saidsecond fin sheets positioned with the inlet and outlet sections of saidindividual core elements are offset rectangular fins positioned toprovide maximum resistance to flow, said plurality of fins positionedwithin said inlet and outlet sections of said warm up tube areindividual fins positioned across the flow in the warm up tube toprovide minimum resistance to flow, said individual core elements arebrazed together with said plurality of individual fin sheets betweensaid core elements and with said warm up tube to form an integral heatexchanger core' 9, The modular heat exchanger of claim 7 and in additionresilient material pads interposed between said heat exchanger and saidheat exchanger core and said heat exchanger core case at points ofsupport.

10. The modular heat exchanger of claim 7 and in addition a source ofcongealable fluid to be cooled.

11. The modular heat exchanger of claim 10 wherein said source ofcongealable fluid to be cooled in a congealable fluid cooled engine andsaid first section of said case is integral with said engine.

12. The modular heat exchanger of claim 10 wherein said congealablefluid is a lubricating oil.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.'3,635,283 Dated January 18, 1972 Inventor (d) David L. Satchwell It iscertified that error appears in the above-identified patent andthat saidLetters Patent are hereby corrected as shown below:

In the Snecification:

Col. '1, line 31, after "case" insert --which-- C01.1, line 75,, after"their' insert --outer-- Col. 3, line 3 1, after "resistance" insert--of-- In the Claims: I

Claim 2, line 7, after "said" insert ---first and said-- line 12, change"he" to --the-- Claim 6, Iine 2, after "cooled" insert "engine-- Claim7, line 4, change "and" to "said-- line 8, change "at" to -to-- line 21,change "and" to --of-- Claim 8, line 1, change "'1" to -7- line 8, after"flow," insert --and-- Claim 9, line 3, cancel "and said heat exchanger"Signed and sealed this 27th day of .1 6 1972.

SEAL) Attest:

EWARD M.FLETCHER,JR. ROBERT GOT'ISCHAIK Attesting Officer 7 Commissionerof Patents F ORM 1 0-1050 IO-69) USCOMM-DC 60376-P69 ILS. GOVERNMENTPRINTING OFFICE I9! O-Jll-JSI

1. A modular heat exchanger comprising: a modular heat exchanger corehaving a plurality of substantially identical individual core elements;and a heat exchanger core case positioned around said core and having afirst section and a second section, said second core case sectiondetachably secured to said first core case section to removably supportsaid core.
 2. The modular heat exchanger of claim 1 wherein saidindividual core elements comprise: a first tube plate; a second tubeplate substantially identical to said first tube plate, the outerperiphery of said first tube plate joined to the outer periphery of saidsecond tube plate to form an enclosure between said second tube plates;restricting means within said enclosure defining an inlet section and anoutlet section within said enclosure; said inlet section of saidenclosure having an inlet header at the one end thereof, said inletheader having an inlet on one side thereof and an outlet on he oppositeside thereof; said outlet section of said enclosure having an outletheader at the one end thereof, said outlet header having an inlet on oneside thereof and an outlet on the opposite side thereof; a first finsheet positioned within said inlet section of said enclosure; and asecond fin sheet positioned within said outlet section of saidenclosure.
 3. The modular heat exchanger of claim 2 and in addition aplurality of individual fin sheets, an individual fin sheet positionedbetween adjacent individual core elements.
 4. The modular heat exchangerof claim 1 wherein said first section and said second section of saidheat exchanger core case are boltably secured to each other.
 5. Themodular heat exchanger of claim 1 and in addition resilient materialpads interposed between said heat exchanger core and said heat exchangercore case at points of support.
 6. The modular heat exchanger of claim 1and in addition a fluid cooled operably associated with said heatexchanger and wherein said first section of said heat exchanger corecase is an integral part of said engine.
 7. A modular heat exchanger fora congealable fluid comprising: a modular heat exchanger core having aplurality of substantially identical individual core elements, andindividual core elements comprising: a first tube plate; a second tubeplate substantially identical to said first tube plate, the outerperiphery of said first tube plate joined at the outer periphery of saidsecond tube plate to form an enclosure between said first and saidsecond tube plate; restricting means disposed within said enclosuredefining an inlet section extending the length of one side of saidenclosure and an outlet section extending the length of the oppositeside of said enclosure, said inlet section communicating with saidoutlet section at the bottom of said enclosure; said inlet section ofsaid enclosure having an inlet header at the upper end thereof, saidinlet header having an inlet on one side thereof and an outlet on theopposite side thereof, said inlet adapted to communicate with the outletof the inlet header and an adjacent core element on one side of saidinlet header and said outlet adapted to communicate with the inlet ofthe inlet header of an adjacent core element on the opposite side ofsaid inlet header; said outlet section of said enclosure having anoutlet header at the upper end thereof, said outlet header having aninlet on one side thereof and an outlet on the opposite side thereof,said inlet adapted to communicate with the outlet of the outlet headerof an adjacent core element on one sidE of said outlet header and saidoutlet adapted to communicate with the inlet of the outlet header of anadjacent core element on the opposite side of said outlet header; afirst fin sheet positioned within said inlet section of said enclosure,and a second fin sheet positioned within said outlet section of saidenclosure; a plurality of individual fin sheets, an individual fin sheetpositioned between adjacent individual core elements below said inletand outlet headers; a heat exchanger core case positioned around saidcore and having a first section at one end of said core and a secondsection at the other end of said core and boltably attached to the firstcase section, said first case section having an inlet to provide a flowof congealable fluid to said core and two outlets to receive a flow ofcongealable fluid from said core; a warm up tube interposed between saidfirst case section and said heat exchanger core; restricting meansdisposed within said warm up tube defining an inlet section extendingthe length of one side of said warm up tube and an outlet sectionextending the length of the other side of said tube, said inlet sectioncommunicating with said outlet section at the bottom of said tube; saidinlet section of said warm up tube having an inlet to receive a flow ofcongealable fluid to the inlet section of said warm up tube from theinlet of said first section of said case and an outlet opposite saidinlet to communicate with the inlet of the inlet header of the adjacentindividual core element; said outlet section of said warm up tube havingan outlet to permit a flow of congealable fluid from the outlet sectionof said warm up tube to the first outlet of said first section of saidcase and conduit means through said outlet section of said warm up tubeto provide communication between the outlet of the outlet header of theadjacent individual core element and the second outlet of the firstsection of said case; a plurality of fins positioned within said inletand said outlet sections of said warm up tube, said fins to provide lessresistance to the flow of congealable fluid than said first and saidsecond fin sheets in the inlet and outlet sections of the individualcore elements; and heat responsive valve means in the first outlet ofsaid first section of said case to permit the flow of cold congealablefluid and restrict the flow of warm congealable fluid.
 8. The modularheat exchanger of claim 1 wherein said first and said second fin sheetspositioned with the inlet and outlet sections of said individual coreelements are offset rectangular fins positioned to provide maximumresistance to flow, said plurality of fins positioned within said inletand outlet sections of said warm up tube are individual fins positionedacross the flow in the warm up tube to provide minimum resistance toflow, said individual core elements are brazed together with saidplurality of individual fin sheets between said core elements and withsaid warm up tube to form an integral heat exchanger core. 9, Themodular heat exchanger of claim 7 and in addition resilient materialpads interposed between said heat exchanger and said heat exchanger coreand said heat exchanger core case at points of support.
 10. The modularheat exchanger of claim 7 and in addition a source of congealable fluidto be cooled.
 11. The modular heat exchanger of claim 10 wherein saidsource of congealable fluid to be cooled in a congealable fluid cooledengine and said first section of said case is integral with said engine.12. The modular heat exchanger of claim 10 wherein said congealablefluid is a lubricating oil.